Regarding ISA/PCI transfer speeds:
ISA (Industry standard architecture) ran in 8bit and 16bit transfer modes. PCI (Peripheral Component Interconnect) ran in 32 and 64bit transfer modes so I would not think of it as a 6 inch long PCI as PCI transfer rates are bus mastered and much faster than ISA and the form factor is often larger and smaller than 6inches. For example, the Sound Blaster AWE32 was a full-length ISA card, measuring 14 inches. As well many 8bit and 16bit ISA cards were not nearly 6 inches long thus the length was even more flexible than PCI.
Regard:
The bottom right hand card is a 4 inch 16bit ISA adapter, the other two are five inch and 3.5 inch 32bit PCI.
One can think of the ISA card as a multi-length legacy (minimum, medium and long) slot card and will then be correct.
R
